Bridge balancing circuit

Abstract

A bridge balancing circuit includes a bridge having a resistance change type sensor, a differential amplifier for extracting a voltage difference across two central nodes of the bridge, a comparator connected to the output terminal of the differential amplifier, a D/A converter an output terminal of which is connected to one of the two central nodes, and a controller for controlling the D/A converter. The differential amplifier and the comparator automatically detect a balanced point of the bridge, and the controller maintains a balanced state of the bridge.

What is claimed is: 
     
       1. A bridge balancing circuit comprising: a bridge having a resistance change type sensor;   a differential amplifier for extracting a voltage difference across two central nodes of said bridge;   a comparator connected to an output terminal of said differential amplifier;   a D/A converter an output terminal of which is connected to one of said two central nodes; and   a controller for controlling said D/A converter,   wherein said differential amplifier and said comparator automatically detect a balanced point of said bridge, and said controller maintains a balanced state of said bridge.